What screw schedule for marine poly

[Florida]

I am installing marine grade, high density polyethlene on my trailer bunks.
The poly is 70" X 3.5" x .5". The lumbar is pressure treated and the aluminum boat weighs 400lbs.
I have a few questions for anyone that knows about hardware.

What size SS wood screw should I use for this stuff?
What size pilot hole?
How deep should I countersink the screw heads?
What should the screw schedule be?

I bought these slicks for 20 dollars each from a local plastic supplier. Cant wait to try the out

Thanks for the help

 

[NYBo]

Re: What screw schedule for marine poly

I think 2 #10 flathead wood screws every 12", countersunk to 1/4" below the surface will be plenty. You're talking about a fairly light load on a slippery surface, so I don't think you're going to need to worry about shearing off the screws.

 

[Bondo]

Re: What screw schedule for marine poly

I think 2 #10 flathead wood screws every 12", countersunk to 1/4" below the surface will be plenty. You're talking about a fairly light load on a slippery surface, so I don't think you're going to need to worry about shearing off the screws.

Ayuh,... Or even #8s, doubled on the ends, 'n single screws each foot or so...

There ain't gonna be much of Any stresses anyways...

 

[Av8nBill]

Re: What screw schedule for marine poly

I installed similar strips from Surfix this last season and they came with # 10s, countersunk 1/4" and spaced about 18 -24" apart. I haven't had any issues and my 14' Jon with motor and all the gear is probably 400 - 500 lbs., so you should be good with the above advice. If you want, for added peace of mind you could use some 5200 or similar between the wood and the strips before you screw 'em down.